KPL/IK Star Tracker Instrument kernel =========================================================================== This instrument kernel (I-kernel) contains Solar Orbiter Star Trackers (STR) optics, detector, and field-of-view parameters. Version and Date --------------------------------------------------------------------------- Version 0.0 -- July 6, 2017 -- Marc Costa Sitja, ESAC/ESA Initial release. References --------------------------------------------------------------------------- 1. ``Kernel Pool Required Reading''. 2. ``Frames Required Reading''. 3. ``C-Kernel Required Reading''. 4. Solar Orbiter Spacecraft Frames Definition Kernel. 5. ``APS Autonomous Star Tracker (AA-STR)'', SOL-B.SG-RP-00001, Selex ES, F. Carnesecchi, Revision C, 16th September 2013. IContact Information ----------------------------------------------------------------------------- If you have any questions regarding this file contact SPICE support at ESAC: Marc Costa Sitja (+34) 91-8131-457 mcosta@sciops.esa.int, esa_spice@sciops.esa.int or the Solar Orbiter Science Operations Center at ESAC: sol_soc@esa.int Implementation Notes ----------------------------------------------------------------------------- This file is used by the SPICE system as follows: programs that make use of this frame kernel must "load" the kernel normally during program initialization. Loading the kernel associates the data items with their names in a data structure called the "kernel pool". The SPICELIB routine FURNSH loads a kernel into the pool as shown below: FORTRAN: (SPICELIB) CALL FURNSH ( frame_kernel_name ) C: (CSPICE) furnsh_c ( frame_kernel_name ); IDL: (ICY) cspice_furnsh, frame_kernel_name MATLAB: (MICE) cspice_furnsh ( 'frame_kernel_name' ) PYTHON: (SPICEYPY)* furnsh( frame_kernel_name ) In order for a program or routine to extract data from the pool, the SPICELIB routines GDPOOL, GIPOOL, and GCPOOL are used. See [2] for more details. This file was created and may be updated with a text editor or word processor. * SPICEPY is a non-official, community developed Python wrapper for the NAIF SPICE toolkit. Its development is managed on Github. It is available at: https://github.com/AndrewAnnex/SpiceyPy Naming Conventions ----------------------------------------------------------------------------- Data items are specified using ''keyword=value'' assignments [1]. All keywords referencing values in this I-kernel start with the characters `INS' followed by the NAIF SOLO instrument ID code, constructed using the spacecraft ID number (-144) followed by the NAIF three digit ID number for one of the STR data item. These IDs are as follows Instrument name ID -------------------- ------- SOLO_STR-1 -144051 The remainder of the name is an underscore character followed by the unique name of the data item. For example, the SOLOHI boresight direction in the SOLO_STR frame (see [2]) is specified by: INS-144051_BORESIGHT The upper bound on the length of the name of any data item identifier is 32 characters. If the same item is included in more than one file, or if the same item appears more than once within a single file, the latest value supersedes any earlier values. Overview --------------------------------------------------------------------------- From [5]: The Autonomous Star Tracker (STR) is an equipment whose function is to provide optical measurements to support navigation and attitude measurements throughout the Solar Orbiter spacecraft mission. AA-STR for Solar Orbiter consists of an unique and compact assembly that includes the following modules: - An electro-optical module including the optical system that images a zone of the sky on the APS detector. The APS temperature is kept to its operative value (-5 def) by a thermo-electric cooler. - The electronics to control the APS detector, to process the pixel data and execute the SW program for pattern recognition and attitude estimation and data /command exchange. - The power supply for interfacing the power primary bus. - A baffle configuration, providing appropriated protection against light from the Sun, Earth or other bright objects outside the FOV. - A main structure that supports the above indicated modules. The optical system has been designed to produce a 20 degrees full cone over the APS physical size. This FOV, combined with the achievable detection limits, provide adequate sky coverage for pattern recognition and tracking purposes. Summary of STR Characteristics (same for STR-1 and 2) Wavelength range (nm): 500 - 900 Field of view (degrees): 20 (full cone) Number of pixels: 1024 x 1024 Pixel Size (micrometer): 18 Pixel Angular Size (IFOV) (arcsec): 71.5 Relative aperture (F/Number): F/1.48 Effective Focal length (EFL) (mm): 51.9 Distortion 0.72% at 10 deg Spot Size (pixels) 2 to 4 Mounting Alignment --------------------------------------------------------------------------- Refer to the latest version of the Solar Orbiter Frames Definition Kernel (FK) [1] for the Star Tracker reference frame definitions and mounting alignment information. FOV Definitions --------------------------------------------------------------------------- This section contains definitions for the Star Tracker FOVs. These definitions are provided in the format required by the SPICE (CSPICE) function GETFOV (getfov_c). As in [3] the Star Tracker detector FOVs are defined with respect to the corresponding Star Tracker frames to be squares with the half angular extent of 8.235 degrees and the boresights along the +Z axes of the corresponding frames. These FOV definitions use angular extent style specification. \begindata INS-144051_FOV_FRAME = 'SOLO_STR-1' INS-144051_FOV_SHAPE = 'CIRCLE' INS-144051_BORESIGHT = ( 0.0 0.0 1.0 ) INS-144051_FOV_CLASS_SPEC = 'ANGLES' INS-144051_FOV_REF_VECTOR = ( 1.0 0.0 0.0 ) INS-144051_FOV_REF_ANGLE = ( 10 ) INS-144051_FOV_ANGLE_UNITS = 'DEGREES' INS-144052_FOV_FRAME = 'SOLO_STR-2' INS-144052_FOV_SHAPE = 'CIRCLE' INS-144052_BORESIGHT = ( 0.0 0.0 1.0 ) INS-144052_FOV_CLASS_SPEC = 'ANGLES' INS-144052_FOV_REF_VECTOR = ( 1.0 0.0 0.0 ) INS-144052_FOV_REF_ANGLE = ( 10 ) INS-144052_FOV_ANGLE_UNITS = 'DEGREES' \begintext Platform ID --------------------------------------------------------------------------- This number is the NAIF instrument ID of the platform on which the detectors are mounted. For both Star Trackers this platform is the orbiter. \begindata INS-144051_PLATFORM_ID = ( -144000 ) INS-144052_PLATFORM_ID = ( -144000 ) \begintext End of IK file.